Spark-plug



A KLEVER.

SPARK PLUG. APPLlCATiON FILED JULY 17.1919.

1,340,899. awnt d M y 25, 1920,

FIG.!.

' groove 5 in UNITED srn'rss PATENT orrics.

ARCHIE KLEVER, OF HANNIBAL, MISSOURI.

SPARK-PLUG.

Specification of Letters Patent.

Patented May 25, 1926.

Application filed July 17, 1919. Serial No. 311,401.

the parts hereinafter fully described and claimed.

In the drawings, Figure 1 is a longitudinal section through aspark plug constructed according to this invention. Fig; 2 is a plan View of the same.

The plug or tubular body portion 2 is formed of metal and is screwed into or otherwise secured to the engine cylinder. A. sleeve 3 of insulating materialis secured in the plug 2. This sleeve preferably has tapering end portions, and it has a circumferential rib 4 at its middle part. This, rib 4 is rounded or is made of hemispherical outline, and it is secured in a corresponding the outer end portion of the plug. The rib fits tightly in the groove, and the thin metal or lip 6 atthe top of the plug is pressed down over the rib, after the rib has been placed inpositiomso as to secure the sleeve 3 in place.

The inner end of with a flaring depression or recess the sleeve is provided 7, and a wire or rod. electrode 8 is secured centrally in the sleeve so that its end comes levelwith the bottom of the recess which is'of the same diameter as, the wire. A metal or wire ring 10 is provided, and is connected to the plug 2 by a stem 12, or in any other suitable manner. This ring is arranged to bear on the end 14 of the sleeve around the larger end of the recess, and the end 14: of the sleeve is preferably rounded. ring may be used in place of the wire ring shown, which will form a spark gap with Any other form of the end oi the central wire 8 in the said flaring recess.

The spark is concentrated in this spark gap, and is caused to pass over the flaring wall of the recess and thereby keep it free from all deposit of carbon, which is a great source of trouble in spark plugs as ordinarily constructed.

Vhat I claim is: p

In a spark plug, a body portion, a sleeve of insulating material secured in the body portion and having a flaring recess at its inner end, a wire electrode secured in the sleeve with one end-at the bottom of the recess, and an electrode formed of a ring of wire and provided with a stem for securing it to the body portion, said ring being arranged in contact with the end of the sleeve around the larger 'end of the said recess.

In testimony whereof I have aflixed my signature.

ARCHIE KLEVER. 

